Blindstitching-machine.



M. HEMLEB.

BLINDSTITGHING MACHINE.

APPLICATION FILED NOV. 9, 1907.

Patented July 29, 1913;

3 SHEETS-SHEET l.

ATTUR/VEY M. HEMLEB.

BLINDSTITCHING MACHINE.

APPLIUATION FILED Nov. 9, 1907.

Patented July 29, 1913.

imm

wf/vrom v7 Arronlvfr M. HBMLEB. BLINDSTITGHING MACHINE.

APPLICATION FILED NOV. 9, 1907.

1,069,01 O. Patented July 29, 1913.

3 SHEETS-SHEET 3.

Eig-1D' Br ATTURNEY 'UNITED STATES' PATENT OFFICE.

MARTIN HEMLEB, ELIZABETH, NEW JERSEY, ASSIGNOR T0 THE SINGER MANUFAC- TURING COMPANY, A CORPORATION F NEW JERSEY.

BLrNns'rIToHrNe-MACHINE.

Specication of Letters Patent. Patented July 29 1913 Application led November 9, 1907. Serial No. 401,367.

' specification, reference being had therein to the accompanying drawings.

Many machines have been devised, in the past several years for performing blind-v stitching upon the hems at the bottoms of the legs of trousers and for general operations of this class, all of which have been open to certain more or less serious objections. One of the chief requirements for successful work of this character has been 4found to be operationv upon superposed plies of fabric with the minimum amount of distortion at the. stitching point, and the present improvement is embodied in a machine in which the material adjacent the stitching point is permitted to lie substantially 'fiat a depending bearing bracket in which is4 journaled the horizontal rotary hook-shaft provided with a loop-taking hook adapted to coperate with Vthe needle -and havlng an axial thread-cavity containing a bobbin case,

a space being providedfin front of the hook for access to the contained bobbin to permit the renewal'of the secondary thread'supply without. disturbing the hoo-k, Whichis connected by suitablegearing with the for- Vward portion of the mainshaft to rotate at twice the speed of the latter. To provide clearance for the body of th work between the stitching point and the upright portion of the frame,-the forward portion of the Work-sustaining hornis ele vated adjacent to the needle-path and a vertically moving work-support is slidingly mounted in such outer portion of thel horn .tom view of the machine.

and provided with a Work-engaging rib disposed transversely of the horn, to which rib 1s fitted the lower operative face of the spring-actuated presser-foot, the Work-support having a short project-ion directly beneath the needle-path for crimping the work, which projection is received within a corresponding recess in the operative face of the presser-foot. The Work-support is provided with feed openings'to receive the feed-dog which is actuated for each stitchforming operation, while the work-support is successlvely raised and lowered for consecutive stitch-forming operations to insure the formation of stitches alternately through and above the fabric in the production of an overseam, the raising of the worksupport serving to lift the fabric clear of the feed-dog so as to rob the same of its normal action upon the fabric fo-r each alternate stitch-forming operation.

The mvention will be understood by reference to the annexed drawings, in which- Figure 1 is aside elevation, partly in section, and Fig. 2 is a plan of a machine embodying the present improvements. Fig. 3 1s a frontlelevation of the machine with the face-plate and end cap of the work-sustaining horn removed, Fig. el a transverse section of the same midway of the frame, and looking forwardly, andv Fig. 5 the bot- Fig. 6 is a sectional elevation of the machine through the upright portion of the bracket-arm and looking rearwardly. Fig. 7 is a perspective view of the forward portion of the of a po-rtion of the feed controlling mech-` anislu, and Fig. 9 a similar view of the feed regulating lever. Fig. 1() is a perspective view of the work-support; Figs. 11

vand 12 are perspective views of the presser- 'machine Fig. 8 is a perspective view 3x which has a forwardly extending worksupporting horn or bed 4 with raised outer end 5. The base is provided with a series .of feet 3xx extending outwardly below the lower side of the horn 4 whereby' the latter is spaced 4above the point of support of the machine frame upon the work table to which it is bolted, so as to permit of the stitching of tubular articles of -comparatively small size, such as the sleeves or legs of garments.

fThe main-shaft 6 is journaled longitudifulcrum 17 within the head 2 of the bracketarm. v

The ball-crank pin 11 is connected by means of a pitman 18 with a ball-stud 1.9

at the angle of the bent needle-lever 20 having a fulcrum-pin 21 within the head 2 of the bracket-arm and disposed transversely of the main-shaft, the needle-lever being provided at its lower end with a transverse needle-,socket in which is secured by means of the clamp-screw 22 the shank of the needle 23 curved concent-rically with the fulcrum-pin 21.

The bracket-arm adjacent the head 2 is provided with a depending plate 24 havingbearing bosses 25 in which 1s journaled the horizontal hook-shaft 26 provided'at its forward end with a revolving hook 27 disposed above the path of circular reciprocatory movement of the needle, and provided in its forward face with an axial thread-case cavity Within which is fitted the usual threadcase 28 having a notch 29 entered by the holding arm 30 and itself provided with a central thread-cavity having an axial bobbin supporting in 31 to receive the removable secondary-t 'read-bobbin 32. The bobbin may be removably applied to the threadcase in the manner represented in the patent to P. Diehl No.A 815,517, dated March 20, 1906. Extending beneath the needle-path and opposite the path of movement of the beak of the hook is the fixed needle-guide 25a whose shank 25b is secured by means of the fastening screw 25 to the forward hookshaft bearing 25.

"The rearward portion of the hook-shaft 26 is provided with an angular gear 33 meshing with a similar gear 34 at the lower end of an intermediate shaft 35 journaled in suitable bearings projecting from the plate 34 and having at its upper end an angular gear 36 meshing with a similar gear 37, but of twice the diameter, mounted upon the forward port-ion of the main-shaft 6, whereby the hook receives two rotations for each rotation of the main-shaft.

The cavity for the moving parts disposedv within the head is closed by means of the usual face-plate 38, and the gearing adjacent the bearing bosses 25 is housed by the t-ical slideways 41 to which are fitted the edges of the transversely arranged slide-plate 42 forming a depending member of the work'- support4 having a substantially horizontal work-engafring member 43 with tapered work-'bending rib '44 extending lengthwise of the same and provided wlth feed-dog slots 45 in the opposite end vportions separated by a central. crimping projection or member 46w`ith which said slots or Vapertures 45 are in partial alinement. The slideplate 42 is provided with a transverse slot 47 entered by a stud 48 carried by a crankarm 49 mounted upon the rock-shaft 50 extending longitudinally of and `journaled within the horn 4. Therearward end of the rock-shaft 50 is provided with `a lateral arm 51 connected by means of a pitman' 52' embraced by "the upright portion 3 of the bracket-arm with the lateral arm 53 of a bellcrank lever having `an upwardly extending arm 54. This bellcrarik lever is provided with a hub 55 itted upon the exterior of a sleeve 56 mounted upon a fixed fulcrum-pin 57 and forming the hub` of a vibrating lever 58 overlying the arm 54 of the said bell-crank lever and provided at its upper end with a roller-stud'59 entering a cam-groove 60 inthe forward face of a camforward portion of' disk 61 having fixed thereto a gear wheel 62 .meshing withV a pinion 63`of-,one-h'alf its size'upon the main-shaft. The arm54 of the 'bellcrank lever is formed with a transverse slot 64 entered by 4a clamp-screw 65 tapped into the lever 58, and adjacent thereto is provided a lateral ear 66 through which- .screw 65 and adjusting of the screw 67 and retightening of the screw (i5-merely serving to adjust the position of the roller-stud 59 in relation to the lateral arm 53 of the bell crank to determine'the initial position of the operative face Vofthe work-support in relation to the top 'of the work-sustaining horn. i

- rlhe feed-rock-shaft 68 is journaled in suitable bearings within the horn 4 and is 73 having-four rectangularly arranged feeding sections corresponding with the apertures 45 of the work-support and passing through the same for engagement with the under side of the work. The slide-bloeit 71 is provided with a transverse slot 74 entered by a stud 75 carried by a lateral arm 76 of the feed-lifting rock-shaft 77 journaled within the horn 4 and provided at its` rearward end with a lateral arm 78 having a pivotal connection with'the lower end* of a pit-man 79 whose opposite end is formed with a strap 80 embracing the usual actuating eccentric 81 on the main-shaft 6. The rearward end of the feed-rock-sha-ft 68 is provided with a lateral arm 82 pivotally bracket-arm and extends transversely of the latter through the usual slot 93 and is provided at its outer end with a set-screw 94 serving as a iin'ger-piece for moving the lever and as a holding means by engagement of the point of the screw with the side of the housing 95 for the gears 62 and 63, which is in practice provided with a cap 96. The feed lifting and advancing eccentrics being mounted upon the main-shaft, effect an operative or feeding movement of the feed-dog for each reciprocation of the needle, while the cam-member 61, turning at onehalf the speed of the main-shaft, and impart-ing a singlel up-and-down movementto the work-support for each rotation, produces alternately a rising and 'a falling movement of the work-support preparatory to the production of each stitch, thus causing it to perform itscycle of movements with one-half the frequency of the feed-dog'.

Opposed to the work-support 43 is the presser-foot 97 having its under or operative face arched to t the work bending rib 44 of the work-support, and provided with a transverse needle-slot 98 and adjacent recess 99 to receive the work-crimping member 46 of the work-support. The presser-foot is provided at the front upon one side of its center with anotch forming a longitudinal guide-shoulder 100 and an inclined undercut,- work-smoothing shoulder 101. The shank of the presser-foot 97 is secured in the usual manner to a presser-bar 102 mounted in the head 2 of the bracket-arm and provided with a collar 103 having a lateral lug 104 engaged by the cam portion 105 of the lifting lever 106 pivotally mounted in the fixed stud-screw 107. Secured in the collar 103 is the usual guide-rod 108 surrounded by the presser-bar spring 109 interposed between the collar 103 and the usual bushing 110 at the top of the head 2 of the bracket-arm, the spring 109 serving to maintain the presser-foot 97 pressed upon the material interposed between the same and the worksupport 43.` The needle-slot 98 is of greater depth than the throw of the liftingcam 105, whereby the accidental lifting of the presserfoot while the needle is in the material is prevented from breaking or injuring the needle.

In the operation of the machine, the work, as for instance, the tubular portion of a garment having the body port-ion a turned over along one margin to form a hem Z) with raw edge c, is introduced between the work-support and the presserfoot,with the`hem at the right and the raw edge c lying against the guide-shoulder 100. As represent-ed in Fig. 7, a portion of such a seam has been stitched, and the presser-foot then elevated for purposes of illustration. The presserfoot having been lowered, the machine is vthe stitch being set by the take-up acting upon the primary or needle-thread. As the roller-stud 59 passes beyond the end of the outer portion of the cam-groove 60, as represented in Figs. 3 and. 6, the work-support is lowered and the feed-dog rises through its slots 45 into engagement with the work which it advances a stitch-length and then drops out of engagement.

The operation of the work-engaging portions of the feed-dog through the parallel apertures 45 in alinement with the workcrimping member 46 enables the feed-dog to engage the work in substantial alinement with the stitching so as to insure precision in the advance of thework, while the formation of the work-bending rib 44 with a flat top and the construction of the arched operative face of the feed-dog to conform therewith permits the upper serrated portions of the feed-dog to be made substantially iat so 'as to avoid crowding the stitched portion of the fabric together as would-'be effected by laterally inclining the serrated feeding surfaces correspondingly with the face of the presser-foot at opposite sides of the recess 99 so as to impair the fiatness of the finished seam. In its nextthrust, t-he needle passes over the'top of the body fabric and hem as represented inI Fig. 15, and theoveredge stitch is formed. As the feed-dog rises for a second feeding action, and before its advance movement begins, the .work-support rises and lifts the work above the feeding surface, whereby the advance movement of the feed-dog fails to advance the work, and the subsequent thrust of the needle again takes place through the work as represented in Fig. 14, and beneath its previous thrust. The operations of the parts as thus described are repeated throughout the length of the seam.

While the timing of the work-support actuating .cam as above described causes the work to be .raised above the operative surface of the feed-dog for each alternate stitch, it is evident that by shortening the outerportion of the cam-groove 60 and properly locating the same, the lifting of the work-support` may be effected between feeding movements of the feed-dog, whereby the material will be advanced a stitch length for each thrust of the needle.

As will be readily seen, the bending of the work by means of the tapered rib 44 of the work-support and arched lower .face of the presser-foot is not effected to facilitate the stitching operation, but its object is to raise the stitching point suiiiciently above the top of the work-sustaining horn or bed to provide ample clearance for the various thicknesses of work to enable it to be readily introduced and removed from the machine, the crimping of the work for the stitching operation being effected by the crimping -member 46 of the work-support 33 in conjunction withhe recess 99 in the presser-foot. In other Words, the taper form of the rib 44 is provided merely to afford a raised seat or projection for the crimping member 46 above the plane of the body of the material which is supported somewhat below the gear casing 39 for-clearance and convenience in handling the work. While the taper form of the rib 44 is obviously very desirable to obviate the disto-rtion of the material by abrupt rectangular bends, it is equally desirable-that the feeding surface of the feed-dog should be at right angles to its pressure Iupon the goods to prevent crowding of the same toward the central line of the seam, and this has been accomplished by flattening that portion of the bending rib 44 through which the feed-dog rises for engagement with the work.

It has been proposed heretofore in blind stitching machines of the present type to mount the loop-taker in a removable bracket in order to provide access for renewal of the secondary thread supply. According to the in two relatively adjustable parts 20 and 20a I connected by means Aof a fastening screw 20h, as represented in Fig. 14. A

As previously stated, the arching of the operatlve faces of the work-support andl presser-foot elevatesthe stitching point, so that thepositions of the needle and the looptaker may be correspondingly elevated, while the dropping of the body of the work-supporting horn or bedl intermediate the stitching positionand the face of the bracket-arm provides ample clearance for the body of the goods in the blind stitching of arments and other articles at a distance margin. It will therefore be seen that the general form of'the frame and location of the operative parts adapts the machine for general use for all classes of blind-stitch work, and renders its scope of operation as broad as that 'of lthe ordinary straight-ahead stitching machines, which has, it is believed, never been attained with anyother blindstitchingk machine heretofore devised.

While the thread-case holding arm 30 may be madestationary, itis herein represented as adapted to receive a slight thread releasing movement similarly to the'lower thread controller of my UnitedStates Patent'No. 785,168, dated March 21,1905.

Having thus set forth the nature of the invention what I claim herein is 1. In a blind stitching machine, the comrom the bination with a frame comprising a bracketarm and a work-supporting bed, and a mainshaft journaled in the bracket-arm, of` a vibrating needle-carrier fulcrumed upon the bracket-arm and movable in a plane sub# sta-ntially parallel with the main-shaft, a needle mounted in said carrier, a circularly moving loop-taker mounted in bearings depending from the bracket-arm upon Aan axis parallel with the main-shaft and vhaving a beak whose path ofmovement is transverse to that of the needle, a work-crimping'member movable toward and from the pathof reciprocation of said needle, an adjacent feed-dog, means for imparting to said feeddog feeding and rising and falling move-l ments for each stitch, and means for imparting to said crimping member rising and falling movements of less frequency than those of the feed-dog. i

2. In a blind-stitching machine, the combination with a frame comprising a bracketarm and aV work-supporting bed adapted for attachment to a :worktable, and a base above the bottom of which thellower side of the bed is spaced to afford a. clear workreceiving space between the lbed and the work table, amain-,shaft journaled in the bracket-arm, and stitchforming mechanism comprising a reciprocating needle and a cooperating loop-taker both sustained by the bracket-arm and operatively connected with the forward portion of the main-shaft, of a work-crimping member movable toward and from the pat-hef reciprocation of'said needle .and an adjacent feed-dog, both mounted Withinsaid work-supporting bed, a cam-member mounted in said bracket-arm and operatively connected with the mainshaft to rotate at a slower Speed, and operativeV connectionsl between said cam and the Work-crimpingmember` and between the main-shaft and the feed-dog, whereby the crimping member is actuated at one-half the frequency of .the feed-dog 4actua-tions.

3. Ina blind-stitching machine, the combination with a frame comprising a bracketarm formed with hollow upright andj horizontal portions and a Work-supporting bed beneath said bracket-arm, 'a main-shaft jour- {naled within said bracket-arm and stitch- "'tormmg mechanism comprising a reciproeating needle mounted upon the bracket-arm and a rotary'loop-taker mounted upon an axis parallel with the main-shaft and having a beak whose path 'of movement 1s transverse tcgthat of the needle, anv intermediate shaft, and angular gearing connectin the same at opposlte ends respectively, wit the .main-shaft'a-nd the said loop-taker, of a Work-crimping member disposed transversely to the needle-path, means for guiding the same, means :tor imparting rising and falling movements to said crimping member, and feeding mechanism for advancing the work;

4.' In a blind-stitching machine, the combination with a frame comprising a bracketlarm and a work-supporting bed,V a mainshaft jonrnaled in the bracket-arm, and stitch-forming mechanism comprising a reciprocating needle and a coperating looptaker both sustained by the bracket-arm and operatively connected with the forward portion of the main-shaft, of a work-crimping vmember movable toward `and away from the path of reciprocation of said needle, a cammember connected with the main-shaft, a Vibrating lever'mounted upon a fixed fulcrum and'deriving its movements from said cam member, a second lever mounted Vto vibrate concentrically with the first named lever and adjustably connected `therewithl in different-,angular relations thereto', operative connections intermediate the secondnamed lever and the said crimping member whereby the latter 1s moved toward and {away from the needle-rpath, and feeding mechanism for advancing theV work.

5. In a blind-stitching machine, the combination with aframe comprising a bracketarm and a work-supporting bed, a mainshaft journaled in the bracket-arm, and stitch-forming mechanism comprising av reciprocating needle and aycoperating looptaker, both sustained by the bracket-arm and operatively connected with the main-shaft, of a work-crimping member movable toward and away from the path of reciprocation of `said needle, means for raising and lowering said crimping member for each alternate stitch, a feed rock-shaft journaled within and extending longitudinally of said 'worksupporting bed, an upwardly extending arm on said feed rock-shatt adjacent the workcrimping member and formed with a slide- Way, a reciprocating block mounted in said slideway, a feed-dog pivotally mounted upon the upper end of said block, means for reciprocating said block in its slideway, and means connected with the main-shaft for oscillatingsaid rock-shaft..

i 6. In a blind-stitching machine, the combination with a frame comprising a bracketarm and a Work-supporting bed, and a mainsha'ft journaled in the bracket-arm, of stitch-forming mechanism comprising a needle-lever carrying a curved eye-pointed needle and mounted upon a ulcrumcarried by the bracket-arm and disposed transversely of the main-shaft, offset cylindrical and ball-crank pins carried by the forward end of the main-shaft, a ball-stud carried by the needle-arm, a pitman connection intermediate said ball-crank pin and 4ball-stud, a bell-crank take-up lever having one arm connected with the cylin'drical crank-pin upon the main-shaft and the otherarm provided with a thread-eye, a link one end of which is pivotally connected to the bracket- -arm and the other end of which affords a fulcrum for the angular or central portion of said take-up, a loop-taker coperating with said needle and carried by the bracketarm, and operative connections between said loop-taker and the main-shaft., a workcrimping member movable toward and away from the path of movement of said needle, a spring-actuated presser-foot opposed to said crimping member, means for shifting said crimping member in respect to the needlepath for each alternate stitch, and feeding mechanism for advancing the work.

7. In a blind-stitching machine, the com- 4bination with a frame comprising a bracketarm and a work-supporting bed, and a mainried by the bracket-arm in fixed transverse shaft journaled 1n the bracket-arm, ot

relation to the main-shaft, a ball-crank carried by the forward end of the main-shaft, a pitman connection intermediatesaid ballcrank and the needle-lever, a rotary looptaker mounted in fixed bearings depending from said bracket-arm and having its axis above and in the plane of the needle-path, said loop-taker being formed with an axial thread cavity and havinga clearance space in front of the same, a bobbin removably sustained wit-hin the thread cavity of said loop-taker, operative connections between the main-shaft and said loop-taker, awork-l crimping member movable toward and away from the path of movement of said needle, a spring-actuated presser-foot opposed to said work-support, means for shifting said crimping member in respect to the needlepath for each alternate stitch, and feeding mechanism for advancingV the Work;

8. In a blind-stitching machine, the combination withl a frame comprising a bracketarml and a Work-supporting bed having an elevated forward end portion, and a longitudinally extending main-shaft journaled in the bracket-arm, of stitch-forming mechanism comprising a needle-lever carrying av curved eye-pointed needle mounted upon a lfulcrum carried by the bracket-arm and disposed transversely of the main-shaft, a crank mounted o-n the forward end of the main-shaft, a pitman connection intermediate said crank and the needle-lever, -a rotary loop-taker mounted-in fixed bearings depending from said bracket-arm and having its axis arranged. permanently above and in the lane of the needle-path, operative eonneetlons between the main-shaft and said loop-taker, a' work-crimping member mounted in the forward end of said Worksupporting bed with itsv operative face disposed above the elevated portion of the latter and movable toward and away from the path of movement of said needle, a springactuated resser-foot opposed to said crimping mem er, means for reciprocating said orimping'member in respect to the needlepath for each alternate stitch, and feeding mechanism for advancing the Work.

In testimony whereof, I have signed my name to this speciication, in the presence of two subscribing witnesses.

- MARTIN HEMLEB. Witnesses: 4

JOSEPH F. JAQUITH, HENRY J. MILLER, 

